The invention relates to a resection instrument, especially for the minimally invasive, subanodermal, submucous removal of hemorrhoidal tissue comprising a narrow oblong carrier means provided with a resection portion for removing tissue on a front part.
Resection instruments for removing parts of tissue during operations at the human body are sufficiently known from the prior art. They have the purpose of separating tissue and removing it from the body. Especially during minimally invasive operations resection instruments have gained an increasing importance, since they allow the selective separation and removal of tissue through smallest body openings within the body in a very precise manner.
Resection instruments are, for example, used for the minimally invasive, subanodermal, submucous removal of hemorrhoidal tissue, whereby the narrow oblong resection instrument is introduced at the point between the anoderm and the skin of the buttock such that the sensitive anoderm is hardly injured. The hemorrhoidal tissue is dissected and fragmented underneath the anoderm by means of ultrasound and resected with the resection instrument only afterwards.
On a resection instrument of the above-mentioned type known from G 298 03 143 is provided a tissue-removing resection cutting means at a front end of the carrier means. The cutters extend through the carrier means and are approximately disposed in the area of cutter openings distributed on the surface area over the circumference of the carrier means. Said resection instrument has on principle proved to be reliable. If it is applied with care and practice in the handling thereof, the tissue can be locally resected with great precision.
The invention is based on the object to improve the resection instrument of the aforementioned type such that tissue can be resected precisely and as gently as possible by simultaneously handling the instrument in the easiest possible way. According to the invention said object is provided with a resection instrument of the aforementioned type characterized in that the resection portion has a trough-like bulge being curved in a convex manner and approximately spoon-shaped in the longitudinal section, with a resection surface provided with a resection means being disposed on the inner side of the trough-like bulge.
The curved, spoon-shaped, trough-like bulge provides for a kind of cavity in which the resection takes place. The instrument can be controlled such that only the parts of the tissue to be removed are passed to the region of the cavity and to the resection surface. The trough-shaped bulge forms kind of a protection so that surrounding parts of tissue are not affected. The tissue is protected on the rear side of the bulge facing away from the inner side, which allows to precisely move along tissue parts with the rear side and to selectively treat bad tissue on the inner side of the instrument.
The trough-like bulge can extend along the carrier means approximately only in a one-dimensional direction. It may optionally also be designed in a spherical manner.
By means of the resection portion designed according to the invention tissue can be resected with great precision, whereby adjacent healthy parts of tissue are hardly affected. The handling of said instrument is very easy.
When using it as hemorrhoidal resection instrument, the instrument is introduced at a small incision in the fringe area between the anoderm, which is the transitional skin at the end of the channel of the anus between the mucosa of the rectum and the outer skin of the buttock, and is moved forward with the rear side of the bulge being adjacent to the anoderm. On the resection surface being adjacent to the inner side of the trough-like bulge hemorrhoidal tissue is removed by means of the resection means. The hemorrhoidal tissue is usually dissected and fragmented with a vibration-surgical unit beforehand.
The carrier means may advantageously comprise an approximately rod-shaped holding portion, which extends in the longitudinal direction, and the trough-like bulge may, deviating from the longitudinal direction, be designed in a fashion that it at least partly bends back to the longitudinal direction in a convex manner. The holding portion extending in the longitudinal direction serves the orientation for the alignment of the resection portion. Deviating from the longitudinal direction the resection surface is then provided in the trough-like bulge in a fashion slightly displaced backwards, so that a localization of the bulge is possible from outside. By means of the bulge bending back to the longitudinal direction the approximately spoon-shaped form is obtained in the longitudinal cross-section, which can be controlled by the handling portion such that only tissue to be removed is passed into the area of the resection surface.
The trough-like bulge does not necessarily have to bend back to the longitudinal direction. Although this configuration is possible, the end of the bulge may also end in a fashion spaced apart from the longitudinal direction. Longitudinal direction preferably relates to a straight line. Likewise conceivable is, for example, also a slightly arch-shaped configuration of the holding portion, whereby the holding portion may also have a short stub-like shape.
According to an advantageous embodiment the bulge may have, starting at the holding portion, a first arch curved outwardly and deviating from the longitudinal direction and, joining the same, a second arch bent in a direction opposite to the first arch, at the inner side of which facing the longitudinal direction at least a part of the resection surface is provided. By means of the first arch the holding portion deviates from the longitudinal direction. Opposite thereto is provided the second arch forming the main part of the bulge and at the inner side of which is provided the resection surface inclined towards the longitudinal direction. The arches may optionally be circular with their central points being arranged on different sides of the instrument, which forms the opposite bending of the radii. The configuration by means of the arches is particularly favorable in view of gentle transitions along the instrument so as to allow the forward movement thereof through a small incision into a body cavity without difficulties.
The resection surface may favorably be limited exclusively to the area of the second arch. Thus, the resection surface is localized with precision and disposed in a protected manner within the through-like bulge in its entire area.
In a special manner at least one suction opening may be provided approximately in the area of the resection surface, which can be connected to a negative pressure source. The tissue to be resected is sucked through the suction opening into the bulge towards the resection portion so that it can be resected. The particularly refers to loose, e.g. pre-fragmented tissue parts. Important healthy parts of the tissue such as muscles, particularly in a tensioned state, are not sucked and, therefore, remain at a distance from the bulge and are not drawn into the cavity.
At least in the area of the bulge the resection portion may optionally be broader than the holding portion. Thus, the area of the cavity can be made to have a larger surface. In a body lumen the resection portion may be applied to a larger surface while the holding portion may have a relatively narrow design for passing the instrument through a smallest possible body cavity.
As a variant of the invention the bulge may have a flat configuration in the cross-section relative to a holding portion of the carrier means. The flat configuration allows the bulge to be easily inserted into narrow body gaps, whereby adjacent tissue is hardly affected.
According to a preferred embodiment a light-dispensing means may be provided on the rear side of the resection portion facing away from the inner side. The light emitted from the light-dispensing means can be used by the operating surgeon as positioning aid. The light has a diaphanoscopic effectxe2x80x94it transmits light through the tissue parts towards the rear side. By means of the light and the shade contours of the surrounding tissue the operating surgeon recognizes the position of the resection portion. The rear side is usually provided close to the outer surface of the body so that the position of the instrument can be recognized due to the light-dispensing means and the instrument can be controlled accordingly. Especially with hemorrhoidal resections the rear side of the resection portion is approximately adjacent to the anoderm, and by means of the light shining through the anoderm the exact position of the resection portion can be recognized.
A light-dispensing means may advantageously be provided at a front end of the resection portion. This arrangement allows the location of the front area of the instrument to be recognized so that the operating surgeon obtains information on the forward movement of the instrument in the body.
In a special manner at least the front end of the resection portion may be provided with an ultrasound unit for dissecting and fragmenting tissue, whereby, in a vibration-surgical manner, the tissue can be dissected and fragmented. In a hemorrhoidal operation the hemorrhoidal tissue may be isolated from the inner sphincter on one side and from the anoderm on the other side. The anoderm thereby remains preserved and the musculus internus undamaged.
As a surgical ultrasonic tool a frequency of, for example, 20,000 to 40,000 hertz may be applied. Thus the hemorrhoidal tissue can be dissected and fragmented selectively and without damaging the healthy tissue. In the following it can be disintegrated and removed by means of the resection means with the result that it can be removed from the area between the sphincter and the anoderm piece by piece.
In accordance with a special embodiment the resection portion may be constructed as an ultrasonic vibration tissue disintegration device for dissecting and fragmenting tissue. If the resection portion itself is constructed as an ultrasonic unit practically the entire resection portion or the entire instrument vibrates so that surrounding bad tissue is dissected while healthy tissue is not affected.
The resection portion may possibly be provided with a rinsing opening joining a rinsing channel to be connected to a rinsing system. Rinsing fluid can be fed via the rinsing opening or optionally it can also be discharged. Thus the area to be treated can be rinsed and possibly freely moving tissue parts can be detached. As rinsing fluid or rinsing medium, for example, physiological salt solution or Ringer""s lactate solution respectively may be applied via the opening. Especially when applying electro-vaporization (tissue vaporization) as resection method this is particularly favorable. The rinsing fluid can either flow back through a rinsing channel of the instrument or escape at the incision point between skin and instrument. For feeding rinsing fluid back also the suction opening may be used. The rinsing fluid may also be used for cleaning the resection means, for example, if the resection opening is apt to be clogged by tissue parts. The rinsing may optionally also be used for cooling purposes.
According to a special embodiment of the invention the rinsing opening may at least area-wise be provided in the resection surface.